Experimental Evaluation of a Self-Contained Circulation-Control Wing

Abstract

A low-speed experimental investigation detailing the design and evaluation of a self-contained circulation-control wing is presented. A moderate aspect-ratio wing (3.34) utilizing a low-Reynolds-number S8036 profile was tested at . The trailing-edge jet was produced using two internal impellers drawing air off the wing tips. The effect of trailing-edge bluntness was examined as was the jet’s quiescent characteristics. Achievable jet-momentum coefficients were low, limiting circulation control to the boundary-layer control regime. Force-balance testing indicated that the circulation-control system could achieve a moderate zero-lift angle-of-attack shift; however, the primary effect of the jet was flow control at high incidence, in which stall was delayed significantly. The blunt trailing edge (Coanda surface) caused a significant increase in the minimum drag coefficient, reducing both the range and endurance parameters.